In the fiber bundle model, the failure mode depends on the range of stress release, once the disorder distribution is fixed in a moderate range. The reason for the different modes of failures is the competition of damage progression due to stress localization near an already damaged region and vulnerable spots at some distance from the damaged region. While the first mechanism promotes a nucleation driven failure, the second leads towards a percolative damage. The critical range that separates these two limits have been studied elsewhere [1]}, [2]}. The underlying mechanism is not only valid for the fiber bundle model [1]}, [2]}, [5]}, [6]}, [7]}, but is also seen in the random fuse model [8]}, [9]} and also in molecular dynamics simulations [10]}. The present study is also a manifestation of these two competing effects. Indeed, for a wide range of stress release, load increases on almost all elements and hence the weaker among those elements break first. Given that there is no spatial correlation between the failure thresholds of the fibers, the damage is percolative. Additionally, the energy released, which is essentially the square of the threshold value, remains small. As the stress release is more and more localized, the maximum energy emitted eventually reaches a peak, which corresponds to the critical value of the localization parameters, beyond which the avalanche size distribution is known to change to exponential form. It is also known that the moments of the cluster size distributions of the damages reach a peak there [11]}. This is the optimal point where the stress release is sufficiently wide so as to sample the vulnerable fibers and yet sufficiently localized such that the stress concentration on those fibers are high enough. The maximum sizes are therefore seen around this region (see Figs. REF , REF ). Upto this point, therefore, the `equivalence' of the avalanche size and energy are valid (\(s\)  and \(E\)  reach a linear relation). Beyond this point, these two quantities are to be considered separately.
